Re: Digitech Trio -- anyone use one?
I have had one for about 2 months, and really really like it.
I have not yet had any difficulties teaching it anything, even with very complex jazz chords, but syncopated rhythms can be tough for it, and starting any measure with just the bass note of the chord is a no-no as well.
Best thing to do is to break the song you're writing or song you're teaching it down to where you strum the chord in an approximation of the rhythm using only on and off beats and nothing in between (no dotted 8ths, or smaller divisions). It is also very important to get that footswitch stomped on exactly the first beat of the next bar after you're done teaching it.
Once the chord progression is in there, you can tweak to your heart's content to change the feel, speed, and density of the backing track, but you do have to play the "learning" mode in a deliberately simplified manner to get things going. You certainly can just play cowboy chords, one per measure to get it in there, but it will not do as good of a job pre-selecting the right "feel" if you do it that way. You will instead have to surf through the available styles within the genre you have selected once you get the track going.
Beyond that, this is definitely one of the greatest practice tools yet invented for guitar...and lead guitar in particular. You can try multiple scales and modes over given chords or progressions to learn what does and doesn't work, and it helps you understand why. It can illustrate to you graphically what the difference is between playing an F# Blues Box over the top of a song that is all dominant 7ths, and playing modal mixolydian over each of the chords. You can then grow as a musician when you truly understand the sound you're going for and what methods to use for them. You can practice switching back and forth between different soloing methods mid song...and how to blend several different sounds in a way that sounds uniform. It can show you how different rhythm guitar styles work with or against the bass and drums...you can learn how to pull your comping back so the song is left open enough for leads to be heard, but still gets the chordal content out there...
I think one of these pedals should come with every electric guitar purchase! Amazing tool for pushing your guitar playing in whatever direction you're needing to work on, in the context of playing with other players.
I know a lot of people have bought them and thought "how lame...this is just a casio keyboard for guitarists" and in a way it is...but its how you use it that gives it value. Hopefully they (digitech) will start providing updates via the USB port that improves some of the sounds and makes things more realistic, instead of that "dippy at times" casio keyboard-esqu sound to the backing tracks...but some of them sound pretty good.
I route mine through a small bass practice amp (solid-state 20W) then use an A-B pedal to switch my guitar to my guitar amp once the backing track is going...things definitely sound pretty good this way. Not good enough to record an album, but good enough to do busking on the street corner I would say.